Machine for folding sheet metal



Dec. 10, 1929. F. MENNE MACHINE FOR FOLDING SHEET METAL Filed March 17, 1928 Patented Dec. 10, 1929 PATENT OFFICE FRITZ MENN'E, OIE WEIDENAU-ON-THE-SIEG, GERMANY, ASSIGNOR TO HERMAN F. HOEVEL, OF NEW YORK, N. Y.

MACHINE FOR FOLDING SHEET METAL Application filed March 17, 1928, Serial No. 262,406, and in Germany March 5, 1927.

My present invention relates to machines for the reliable folding of sheet-metal plates of different lengths. As a rule, such plates will be folded at the middle, but the mach ne disclosed herein is also adapted for folding a sheet-metal plate at other points. The object of the invention is to provide a folding machine which will hold the plate or blank securely and form the fold therein graduall 7 r satisfactory and preferred embodiment of my present invention is shown in the accompanying drawings, in which Fig. 1 1s a side elevation of the improved machine, Fig. 2 is a plan view thereof, and Fig. 3 is an end elevation of a carriage used in such machine.

In the embodiment illustrated, to the upper ends of four stationary columns 2 is secured rigidly an abutment plate a. This stationary plate is opposed by a movable presser plate Z), centrally pivoted at b, to the upper end of a pressure link g. The lower end of this link is pivoted at g to the head Z of a plunger 7", operated hydraulically or in anyother suitable manner. At one side, the plunger head Z is guided along two of the upright columns a and engages the lower ends of two coiled springs c surrounding said columns. The upper ends of said springs engage thimbles or sleeves 0 movable along said columns and formed at h with a pivotal connection forming a rocker bearing for the adjacent portion of the presser plate 6. At the opposite side, the plunger head is connected with a depending rod 2', carrying at its lower end a support 2" on which rests a coiled spring y, the upper end of which carries a washer j adapted to engage a stationary stop is, after said rod and spring have moved upward a certain distance from the position shown in Fig. 1. V

In connection with the parts described above, I employ a carriage to bring the blank or sheet-metal plate 03 into co-operative relation to the abutment plate or member a and the presser plate or member I). I have represented this carriage as a car y running on a horizontal track 00 and provided with supports m extending lengthwiseof the carriage the press proper overhang and path and movable vertically on the car, being for this purpose pivoted about a transverse horizontal axis, as indicated at n. Those ends of the supports m which are nearest preferably have rounded ends 6 bent downwardly.

In operation, the metal sheet or blank (Z is placed on top of the supports m, and the carriage y is then moved along the track .02 toward the press proper. The attendant swings the supports m down at the ends nearest the press, thereby causing the blank or sheet d to slide down as indicated in Fig. 1, so that the forward edge of the sheet will be below the level of the presser plate 6, the latter being at that time inclined as indicated. The supports m are then again restored to a horizontal position while the carriage continues to move toward the right in Fig. 1. This will bring the overhanging portion of the sheet (Z in contact with the left-hand edge of the presser plate 6, and as the supports m are then at a level above said left-hand edge, the further advance of the carriage will bend thesheet into a loop, as indicated at the right-hand portion of Fig. 1, said loop being situated above the presser member 6, and the supports m being within the loop. The rounded ends 6 of said supports serve to form the loop without bending the metal too sharply. The two ends or transverse edges of the sheet-metal plate (Z are thus brought toward each other, and may be held fast temporarily, at their central portions, by means of tongs, clamps, or other suitable tools. The two supports m are spaced so as permit such tools to be applied readily; The plunger f and the presser plate I) are then raised to exert an upward pressure on the folded sheet d and hold it in place while the carriage y is moved to the left and withdraws the supports m from within the loop. As the two layers of the sheet d converge toward the left, the sheet would not be very liable to follow the supports m as the latter are retracted, even if no material upward pressure were exerted by the presser member 6. To facilitate withdrawal of the supports m from the folded sheet 03, they are preferably of less width 1 Q at points toward their central portions than at their free ends. I also consider it best to project the rounded ends 6 laterally toward each other, as shown in Figs. 2 and 3, so as to bring them in contact with a greater surface of the sheet metal at the bend or fold.

When the plunger 7 rises, that portion of the presser member 6 which rests on the springs 0 will first come in contact with the folded plate of sheet metal, and will hold or clamp it in position. As the presser member is raised farther, it will swing gradually from the inclined position illustrated to a horizontal position, parallel to the abutment member a. This will compress the springs 0 and might have a tendency to cause the plunger head Z to bind on those columns a around which the springs c are coiled. To obviate this, I have provided the spring j which is arranged to engage the stop k at the time the compression of the springs 0 begins, so that the spring by counteracting the springs 0, will keep the plunger head from binding on the guide columns 2.

Various modifications may be made without departing from the nature of my invention as set forth in the appended claims. For instance, the function assigned to the springs c, 9' might be performed by other instrumentalities. The plunger f, instead of being actuated by hydraulic pressure, might be operated in some other suitable way, for instance mechanically by toggle levers. The carriage 1 might be power-operated instead of pushed by hand. For the purpose of withdrawing the supports m from the folded plate of sheet metal, they might also be arranged to swing laterally, about vertical axes, but such arrangment I consider less desirable because it would require the. omission of one of V the columns 2 on the side toward the carriage y, in order to provide a clear path for the lateral swinging of the supports m when they are to be withdrawn from the folded sheet 0?.

I claim:

1. A machine for folding sheet metal, comprising two companion members movable relatively to each other and adapted to engage a folded sheet on opposite sides to de-' velop a compression force thereon, one of said members being mounted to swing so as to vary the angle it forms with the other v member, to impart a sort of rolling action to such member during the folding operation and to develop an initial folding pressure on said sheet, and means for giving the swinging member normally a position oblique with reference to the other member.

2. A machine according to claim 1, in which a spring device engages the swinging member at one side to urge said side toward the companion member and give the swing ing member normally a position oblique with reference to the other member.

3. A machine for folding sheet metal, comprising stationary columns, a stationary abutment member carried by said columns, sleeves slidable along the columns at one side of the machine, a presser member movable toward and from said abutment member and in rocking engagement with said sleeves to swing about a transverse axis, and springs engaging said sleeves with a tendency to urge them toward said abutment member.

4. A machine for folding sheet metal, comprising stationary columns, a stationary abutment member carried by said columns, sleeves slidable along the columns at one side of the machine, a presser member movable toward and from said abutment member and in rocking engagement with said sleeves to swing about a transverse axis, a pressureexerting device including a head guided along said columns and movably connected with the central portion of said swinging member. springs interposed between said head and said sleeves and urging the latter toward the abutment member, and a counter-acting spring device connected with said head on the side opposite to said sleeves.

5. A machine for folding sheet metal, comprising stationary columns, a stationary abutment member carried by said columns, sleeves slidable along the columns at one side of the machine, a presser member movable toward and from said abutment member and in rocking engagement with said sleeves to swing about a transverse axis, a pressure-exerting device movably connected with the central portion of said swinging member, and springs interposed between said device and said sleeves and urging the latter toward said abutment member.

6. A machine for folding sheet metal, comprising stationary columns. a stationary abutment member carried by said columns, sleeves slidable along the columns at one side of the machine, a presser member movable toward and from said abutment member and in rocking engagement with said sleeves to swing about a transverse axis, a pressure-exerting device including a head slidable along said columns, a link the ends of which are connected pivotally with the central portions of said head and of said swinging member respectively, springs interposed between said head and said sleeves and urging the latter toward the abutment member, a counteracting spring device connected with the said head on the side opposite to said sleeves, and a stop co-operating with said counter-acting spring device.

7. A machine for folding sheet metal, comprising two companion members movable relatively to each other and adapted to engage a folded sheet on opposite sides, and a carriage movable toward and from said companion members and provided with an overhanging support adapted to co-operate with one of said members to impart an initial fold to said sheet and to subsequently introduce said folded sheet between said members.

8. A machine according to claim 7, in which the support consists of spaced members extending lengthwise of the carriage path.

9. A machine according to claim 7, in which the support is connected with the carriage movably to vary the position of the sheet relatively to said members.

10. A machine according to claim 7, in which the support is pivoted to the carriage about an axis transverse to the carriage path.

11. A machine according to claim 7, in which the free end of the overhanging support is rounded.

12. A machine according to claim 7, in which the support consists of spaced members which are greater in width at their free ends than at intermediate points toward the carriage.

13. A machine according to claim 7, in which the support consists of two spaced members extending lengthwise of the carriage path and provided at their free ends with projections extending toward each other to increase the width of the support at its free end.

In testimony whereof I have signed this specification.

FRITZ MENNE. 

